Simultaneous bilateral contrast transcranial doppler monitoring in patients with intracardiac and intrapulmonary shunts.

The prevalence of a right-to-left intracardiac shunt, demonstrated by echocardiography and transcranial Doppler sonography has been shown to be higher in stroke patients than in normal controls. The aim of this study was to assess the sensitivity and specificity of contrast transcranial Doppler sonography in comparison to transesophageal echocardiography in the detection and differentiation of intracardiac and intrapulmonary shunts and to correlate the transcranial Doppler findings with clinical outcome and morphological findings. Forty five consecutive stroke patients with suspected paradoxical embolism were entered into the study. In all 25 patients with middle cerebral artery stroke of the left (56%) or right (44%) territory and echocardiographic demonstrated patent foramen ovale (80%) or intrapulmonary shunt (20%), simultaneous bilateral transcranial Doppler sonography of the middle cerebral arteries was performed after contrast medium injection during rest and valsalva straining under standardized and optimized conditions. Overall sensitivity for the detection of a right-to-left shunt by contrast transcranial Doppler sonography was 97% and overall specificity was 70%. Bilateral appearance of microbubbles, microbubble count and time delay of microbubble appearance significantly increased after valsalva straining. In patients with intracardiac shunts, a significantly higher microbubble count (32 vs. 13 in patients with an intrapulmonary shunt) and a shorter time interval of microbubble appearance (11 vs. 14 s in patients with intrapulmonary shunts) was observed. There was no correlation between the side and numerical distribution of microbubble count and the location and severity of the current clinical symptoms, as well as between microbubble count and presence and hemispherical distribution of brain infarcts. Transcranial Doppler sonography is a highly sensitive method for the detection of right-to-left shunts, whether of cardiac or pulmonary location. However. no correlation was found between the side and number of microbubbles counted and the clinical symptomatology.

[Evaluation of vascular risk factors in patients with Parkinson syndrome]. / Evaluation vaskulärer Risikofaktoren bei Patienten mit Parkinson-Syndrom.

A vascular etiology of Parkinson's disease (PD) has been long debated. In order to search for an ischemic basis of PD we assessed the clinical symptomatology of a consecutive group of 60 PD patients and compared their frequency of cerebrovascular risk factors, carotid atherosclerosis and ischemic brain lesions with age-matched groups of stroke patients and normals. There were 16 (27%) subjects with PD who also had symptoms of cerebrovascular disease. The frequencies of carotid stenoses, ischemic brain lesions and most of cerebrovascular risk factors seen in the latter group was comparable with those of stroke patients and significantly higher than in the investigational subsets of patients with "pure" PD and normals. Only one (1.6%) individual with PD presented signs suggestive of an ischemic etiology of parkinsonism. These findings suggest that cerebrovascular disease occurs in approximately one fourth of patients with PD, but seldomly is causally related.

EEG, CT and neurosonographic findings in patients with postischemic seizures.

Seventy-two patients with postischemic seizures were evaluated with electroencephalography (EEG), computerized tomography (CT) and neurosonography. There were 24% early-onset and 76% late-onset initial seizures. Early-onset seizure was more likely to be simple partial (53%), whereas late-onset seizure was more likely to be primarily generalized (56%). 76% early-onset and 80% late-onset seizures were single. Status epilepticus was more frequent in early-onset that late-onset seizures (p = 0.023). The possibility of recurrence was greater in late-onset than early-onset seizures (p < 0.001). 88% patients had EEG abnormalities, and the most common finding was focal slowing. 75% patients had cerebral infarctions on CT scan, and the majority of them involved cortex. 89% postischemic seizures had carotid lesions which mostly were carotid plaques < 50%. We failed to find these data to be useful in predicting the time of onset of initial seizures after acute ischemic stroke and recurrence.

Serial transcranial Doppler sonography in ischemic strokes in middle cerebral artery territory.

The changes in middle cerebral artery (MCA) blood flow velocity were serially evaluated in 31 patients with acute ischemic strokes in the MCA territory using transcranial Doppler ultrasound. In patients with a poor clinical prognosis, MCA mean velocity on the infarcted side (MV1) was significantly decreased within 48 hours after onset, compared with that on the opposite side (MV2) (p < 0.01). However, this change was not significant in patients with a good clinical prognosis. As predictors of poor clinical prognosis, an MV1 of 40 cm/sec or less and an asymmetry index of -20% or less showed positive predictive values of 93 and 88%, with sensitivities of 72 and 83% and specificities of 92 and 85%, respectively. An MV1 slower than 20 cm/sec or an asymmetry index below -50% had a 100% positive predictive value and a 100% specificity, but less sensitivity (17 and 44%, respectively). Combining an MV1 of 40 cm/sec or less with an asymmetry index of -20% or less resulted in a 100% positive predictive value and a 100% specificity, with a relatively high sensitivity of 67%. As predictors of good clinical prognosis, an MV1 faster than 40 cm/sec and an asymmetry index above -20% showed positive predictive values of 71 and 79%, with sensitivities of 92 and 85% and specificities of 72 and 83%, respectively. The clinical prognosis based on MV1 seems particularly reliable for MCA territorial and cortical infarctions.

Neurosonographic findings in dementia.

We performed neurosonographic examinations in 19 patients with vascular dementia (VD) and compared these findings with those in 21 patients with dementia of the Alzheimer type (DAT) and in 20 controls. There were no significant differences in age and sex among these three subject groups. The severity of dementia quantified by the Mini-Mental State Examination and Mattis Dementia Rating Scale did not reveal significant differences between VD and DAT. We found that carotid stenosis > 50% or occlusion was more frequent in VD compared to controls. The mean flow velocities of both the middle cerebral artery (MCA) and the basilar artery (BA) were decreased in VD and DAT compared with controls. This decrease was statistically significant for left MCA, but not for right MCA and BA. However, we did not find any significant differences between VD and DAT for the mean flow velocities of both MCA and BA.

[A study on middle cerebral artery territory infarction with transcranial Doppler sonography].

The transcranial Doppler sonographic findings of 40 patients with middle cerebral artery (MCA) territory infarction were compared with those of 40 controls. The results showed that in the group of acute phase patients there was a large reduction of MCA mean flow velocity (Vm) of the infarcted side compared with the normal hemisphere (P < 0.01) and controls (P < 0.05). At the same time the anterior cerebral artery (ACA) Vm rose on both sides (esp. on the infarcted side) in comparison with controls (P < 0.05). The posterior cerebral artery (PCA) Vm did not change significantly (P > 0.05). In the group of chronic phase patients there were changes similar to the group of acute phase patients in MCA Vm and ACA Vm, but not statistically significant. Follow-up TCD examinations were carried out in 8 cases during the acute phase of stroke. We found that the decreased MCA Vm on the infarcted side returned to normal in 4 cases, remained lower in another 2 cases within 4 weeks after onset. The increased MCA Vm on the infarcted side in 2 cases returned to normal within 2 weeks after onset. Various types of TCD findings in patients with MCA occlusion were described and analysed.